What caused a change in the chemical composition of coastal waters during hurricane floyd?

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

Adepositional also feature that forms where a stream enters a lake or an ocean is a

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?